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class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="tutorial/toh-pt6" title="第六部分：通过 HTTP 来获取并保存英雄数据。" target="_self"><span>6. 从服务器获取数据</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-2 expanded selected ng-star-inserted" title="通过数据绑定构建动态视图" aria-pressed="true"><span>组件与模板</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-2 expanded selected"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 expanded 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target="_self"><span>生命周期钩子</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/component-interaction" title="在不同的指令和组件之间共享信息" target="_self"><span>组件交互</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/component-styles" title="添加专属于某个组件的样式" target="_self"><span>组件样式</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/dynamic-component-loader" title="动态加载组件" target="_self"><span>动态组件</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/elements" title="把组件转换成自定义元素" target="_self"><span>Angular 元素</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/attribute-directives" title="属性型指令把行为添加到现有元素上。" target="_self"><span>属性型指令</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/structural-directives" title="结构型指令可以操纵页面的布局" target="_self"><span>结构型指令</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/pipes" title="管道可以在模板中转换显示的内容。" target="_self"><span>管道</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-2 collapsed ng-star-inserted" title="Angular 的表单" aria-pressed="false"><span>表单</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-2 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/forms-overview" title="表单可以创建集中、高效、引人注目的输入体验。Angular 表单可以协调一组数据绑定控件，跟踪变更，验证输入，并表达错误信息。" target="_self"><span>简介</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/reactive-forms" title="使用 FormBuilder、表单组和表单数组创建响应式表单。" target="_self"><span>响应式表单</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/forms" title="使用指令和 Angular 模板语法创建模板驱动表单。" target="_self"><span>模板驱动表单</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/form-validation" title="验证用户的表单输入" target="_self"><span>表单验证</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/dynamic-form" title="使用 FormGroup 渲染动态表单。" target="_self"><span>动态表单</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-2 collapsed ng-star-inserted" title="Observable 与 RxJS" aria-pressed="false"><span>Observable 与 RxJS</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-2 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/observables" title="" target="_self"><span>可观察对象(Observable)</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/rx-library" title="" target="_self"><span>RxJS 库</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/observables-in-angular" title="" target="_self"><span>Angular 中的可观察对象</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/practical-observable-usage" title="" target="_self"><span>用法实战</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/comparing-observables" title="" target="_self"><span>与其它技术的比较</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-2 collapsed ng-star-inserted" title="Angular 中的模块" aria-pressed="false"><span>NgModules</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-2 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/ngmodules" title="使用 NgModule 让你的应用更高效" target="_self"><span>NgModule 简介</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/ngmodule-vs-jsmodule" title="JavaScript 模块和 NgModule 之间的差异" target="_self"><span>JS 模块 vs NgModule</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/bootstrapping" title="告诉 Angular 如何在根 &quot;AppModule&quot; 中构造和引导应用。" target="_self"><span>应用的根模块</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/frequent-ngmodules" title="介绍最常用的 NgModule" target="_self"><span>常用模块</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/module-types" title="介绍特性模块的几种类型" target="_self"><span>特性模块的分类</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/entry-components" title="关于 Angular 中入口组件的一切" target="_self"><span>入口组件</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/feature-modules" title="创建特性模块，以组织你的代码" target="_self"><span>特性模块</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/providers" title="服务提供商与 NgModule" target="_self"><span>服务提供商</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/singleton-services" title="创建单例服务" target="_self"><span>单例服务</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/lazy-loading-ngmodules" title="惰性加载模块，以提高应用的性能" target="_self"><span>惰性加载的特性模块</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/sharing-ngmodules" title="共享 NgModule 让你的应用现代化。" target="_self"><span>共享 NgModule</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/ngmodule-api" title="理解 NgModule 的那些细节。" target="_self"><span>NgModule API</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/ngmodule-faq" title="回答关于 NgModules 的常见问题。" target="_self"><span>NgModule 常见问题</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-2 collapsed ng-star-inserted" title="依赖注入：创建并注入各种服务。" aria-pressed="false"><span>依赖注入</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-2 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/dependency-injection" title="Angular 的依赖注入系统能够为 Angular 创建的类创建并交付它们所依赖的服务。" target="_self"><span>Angular 依赖注入</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/hierarchical-dependency-injection" title="与组件树平行的注入器树，并支持嵌套的依赖。" target="_self"><span>多级注入器</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/dependency-injection-providers" title="各种提供商类型的更多知识。" target="_self"><span>DI 提供商</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/dependency-injection-in-action" title="依赖注入的使用技巧" target="_self"><span>DI 实战</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/dependency-injection-navtree" title="使用注入器树来查找父组件。" target="_self"><span>浏览组件树</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/http" title="通过 HTTP 协议与远程服务器对话。" target="_self"><span>HttpClient</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/router" title="揭示如何通过 Angular 路由进行基本的屏幕导航。" target="_self"><span>路由与导航</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-2 collapsed ng-star-inserted" title="Angular 动画系统指南" aria-pressed="false"><span>动画</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-2 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/animations" title="Angular 动画的基础技术。" target="_self"><span>简介</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/transition-and-triggers" title="转场与触发器的高级技术。" target="_self"><span>转场与触发器</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/complex-animation-sequences" title="复杂的 Angular 动画序列。" target="_self"><span>复杂序列</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/reusable-animations" title="创建可复用的动画。" target="_self"><span>可复用动画</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/route-animations" title="为路由提供转场动画。" target="_self"><span>路由转场动画</span></a></div></aio-nav-item></div></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-1 collapsed ng-star-inserted" title="把 Angular 用到你的实际工作中的一些技巧" aria-pressed="false"><span>其它技术</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-1 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/security" title="Angular 应用开发中的安全技术。" target="_self"><span>安全</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/i18n" title="把应用模板中的文本翻译成多种语言。" target="_self"><span>国际化（i18n）</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/accessibility" title="设计能被所有用户访问的应用" target="_self"><span>无障碍（a11y）</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-2 collapsed ng-star-inserted" title="Angular Service Worker: 控制应用资源的缓存。" aria-pressed="false"><span>Service Worker 与 PWA</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-2 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/service-worker-intro" title="Angular 对 Service Worker 的实现提升了慢速或不稳定的网络连接下的用户体验。" target="_self"><span>简介</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/service-worker-getting-started" title="在 CLI 项目中启用 Service Worker，并在浏览器中查看效果。" target="_self"><span>快速上手</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/app-shell" title="在 CLI 项目中启用应用外壳。" target="_self"><span>应用外壳</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/service-worker-communications" title="那些能让你和 Angular 的 Service Worker 通讯的服务类。" target="_self"><span>与 Service Worker 通讯</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/service-worker-devops" title="使用 Service Worker 运行应用、管理应用更新、调试以及杀掉正在运行的应用。" target="_self"><span>生产环境下的 Service Worker</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/service-worker-config" title="配置 Service Worker 的缓存行为。" target="_self"><span>Service Worker 配置</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/universal" title="使用 Angular Universal 在服务端渲染 HTML。" target="_self"><span>服务端渲染</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-2 collapsed ng-star-inserted" title="把 AngularJS 应用增量式的升级到 Angular。" aria-pressed="false"><span>从 AngularJS 升级</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-2 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/upgrade" title="把 AngularJS 应用增量式的升级到 Angular。" target="_self"><span>升级步骤</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/upgrade-performance" title="用更灵活的方式把 AngularJS 升级到 Angular。" target="_self"><span>更关注性能的升级方式</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/ajs-quick-reference" title="学习如何把 AngularJS 的概念映射到 Angular 中。" target="_self"><span>AngularJS 与 Angular 的概念对照</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-2 collapsed ng-star-inserted" title="使用共享库扩展 Angular" aria-pressed="false"><span>开发 Angular 库</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-2 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/libraries" title="理解何时以及如何使用和创建库。" target="_self"><span>库概览</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/using-libraries" title="把已发布的库集成进你的应用中。" target="_self"><span>使用已发布的库</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/creating-libraries" title="通过创建、发布和使用你自己的库来扩展 Angular。" target="_self"><span>创建库</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-2 collapsed ng-star-inserted" title="理解原理图" aria-pressed="false"><span>原理图（Schematic）</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-2 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/schematics" title="理解 Angular 如何使用原理图。" target="_self"><span>原理图概览</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/schematics-authoring" title="理解原理图的结构。" target="_self"><span>制作原理图</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/schematics-for-libraries" title="使用原理图来把你的库集成进 Angular CLI 中。" target="_self"><span>库的原理图</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/cli-builder" title="使用构建器定制 Angular CLI。" target="_self"><span>CLI 构建器</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/web-worker" title="在 Angular CLI 中使用 Web Worker。" target="_self"><span>Web Worker</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-1 collapsed ng-star-inserted" title="关于构建、测试和部署的信息" aria-pressed="false"><span>开发工作流</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-1 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-2 collapsed ng-star-inserted" title="理解 AOT 预先编译器。" aria-pressed="false"><span>AOT 预先编译器</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-2 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/aot-compiler" title="学习为何以及如何使用预先编译器。" target="_self"><span>预先编译</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/angular-compiler-options" title="配置 AOT 编译。" target="_self"><span>Angular 编译器选项</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/aot-metadata-errors" title="解决 AOT 编译错误。" target="_self"><span>AOT 元数据错误</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/template-typecheck" title="Angular 中的模板类型检查。" target="_self"><span>模板类型检查</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/build" title="构建应用及为应用启动开发服务器。" target="_self"><span>构建与运行</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/bazel" title="如何配置你的环境，以利用 Bazel 进行构建和测试。" target="_self"><span>使用 Bazel 进行构建</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/testing" title="测试 Angular 应用的技巧与实践。" target="_self"><span>测试</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/deployment" title="了解如何部署 Angular 应用。" target="_self"><span>发布</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-2 collapsed ng-star-inserted" title="与开发环境和工具集成起来" aria-pressed="false"><span>开发工具集成</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-2 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/language-service" title="使用 Angular 语言服务加速开发。" target="_self"><span>语言服务</span></a></div></aio-nav-item></div></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-1 collapsed ng-star-inserted" title="工作空间与项目的结构，及其配置文件。" aria-pressed="false"><span>配置</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-1 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/file-structure" title="Angular 工作区在文件系统中是怎样的。" target="_self"><span>项目文件结构</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/workspace-config" title="&quot;angular.json&quot; 包含供 CLI 命令使用的工作区和项目默认配置。" target="_self"><span>工作区配置</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/npm-packages" title="开发期间和运行期间所需的 npm 包的说明。" target="_self"><span>npm 包</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/typescript-configuration" title="给 Angular 开发者的 TypeScript 配置。" target="_self"><span>TypeScript 配置</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/browser-support" title="浏览器支持与腻子脚本指南。" target="_self"><span>浏览器支持</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-1 collapsed ng-star-inserted" title="Angular 的版本发布实践、更新与升级。" aria-pressed="false"><span>发布信息</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-1 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/updating" title="如何把 Angular 应用和库升级到最新版本。" target="_self"><span>保持最新</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/releases" title="Angular 的版本、发布、支持、弃用策略及实践。" target="_self"><span>发布实践</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/updating-to-version-9" title="支持把你的应用从 8 升级到 9。" target="_self"><span>升级到第 9 版</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/deprecations" title="弃用的 Angular API 和特性汇总。" target="_self"><span>弃用清单</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/ivy" title="关于 Angular Ivy 的编译与渲染管道。" target="_self"><span>Angular Ivy</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-1 collapsed ng-star-inserted" title="Angular 语法、编码、术语汇总。" aria-pressed="false"><span>快捷手册</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-1 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/cheatsheet" title="关于 Angular 常用编码技术的快速指南。" target="_self"><span>速查表</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/styleguide" title="写出 Angular 风格的程序" target="_self"><span>风格指南</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/glossary" title="Angular 中最重要的词汇的简要定义。" target="_self"><span>词汇表</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-1 collapsed ng-star-inserted" title="Angular CLI 命令参考手册。" aria-pressed="false"><span>CLI 命令</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-1 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli" title="CLI 工具介绍、命令、语法" target="_self"><span>概览</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/usage-analytics-gathering" title="管理员如何从用户那里收集使用情况分析。" target="_self"><span>使用情况分析</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/add" title="ng add." target="_self"><span>ng add</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/analytics" title="ng analytics." target="_self"><span>ng analytics</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/build" title="ng build." target="_self"><span>ng build</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/config" title="ng config." target="_self"><span>ng config</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/deploy" title="ng deploy." target="_self"><span>ng deploy</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/doc" title="ng doc." target="_self"><span>ng doc</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/e2e" title="ng e2e." target="_self"><span>ng e2e</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/generate" title="ng generate." target="_self"><span>ng generate</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/help" title="ng help." target="_self"><span>ng help</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/lint" title="ng lint." target="_self"><span>ng lint</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/new" title="ng new." target="_self"><span>ng new</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/run" title="ng run." target="_self"><span>ng run</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/serve" title="ng serve." target="_self"><span>ng serve</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/test" title="ng test." target="_self"><span>ng test</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/update" title="ng update." target="_self"><span>ng update</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/version" title="ng version." target="_self"><span>ng version</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/xi18n" title="ng xi18n." target="_self"><span>ng xi18n</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-1 collapsed ng-star-inserted" style="position:relative" href="api" title="关于 Angular 中类和值的详细信息。" target="_self"><span>API 参考手册</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><div class="mat-divider ng-star-inserted" style="margin:4px 20px;border-top:1px solid #d3d3d3"></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-1 collapsed ng-star-inserted" style="position:relative" href="https://github.com/ng-docs/ng-docs.github.io/issues" title="github 上的中文互助问答区" target="_blank"><span>互助问答</span><mat-icon role="img" class="mat-icon notranslate material-icons mat-icon-no-color ng-star-inserted" aria-hidden="true">open_in_new</mat-icon></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-1 collapsed ng-star-inserted" style="position:relative" href="https://material.angular.cn" title="Angular Material 组件库的中文文档" target="_blank"><span>官方 Material 组件库</span><mat-icon role="img" class="mat-icon notranslate material-icons mat-icon-no-color ng-star-inserted" aria-hidden="true">open_in_new</mat-icon></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-1 collapsed ng-star-inserted" style="position:relative" href="https://ng.ant.design/" title="Ant Design 的 Angular 实现，服务于企业级后台产品。" target="_blank"><span>ng-zorro 组件库</span><mat-icon role="img" class="mat-icon notranslate material-icons mat-icon-no-color ng-star-inserted" aria-hidden="true">open_in_new</mat-icon></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-1 collapsed ng-star-inserted" style="position:relative" href="https://ng.mobile.ant.design/" title="Ant Design Mobile 的 Angular 实现，服务于无线产品。" target="_blank"><span>ng-zorro mobile 组件库</span><mat-icon role="img" class="mat-icon notranslate material-icons mat-icon-no-color ng-star-inserted" aria-hidden="true">open_in_new</mat-icon></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-1 collapsed ng-star-inserted" style="position:relative" href="https://flutter-io.cn/" title="Flutter 中文文档站" target="_blank"><span>友站：Flutter 中文</span><mat-icon role="img" class="mat-icon notranslate material-icons mat-icon-no-color ng-star-inserted" aria-hidden="true">open_in_new</mat-icon></a></div></aio-nav-item></aio-nav-menu><div class="doc-version ng-tns-c18-1"><aio-select><div class="form-select-menu"><button class="form-select-button"><span><strong></strong></span><span>stable (v9.0.0)</span></button></div></aio-select></div></div></mat-sidenav><div class="cdk-visually-hidden cdk-focus-trap-anchor" aria-hidden="true"></div><mat-sidenav-content cdkscrollable="" class="mat-drawer-content mat-sidenav-content ng-star-inserted" style="margin-left:261px"><main role="main" class="sidenav-content" id="guide-displaying-data"><aio-mode-banner></aio-mode-banner><aio-doc-viewer class=""><div style="opacity:1"><div class="github-links"><a href="https://github.com/angular/angular-cn/edit/aio/aio/content/guide/displaying-data.md?message=docs%3A%20请简述你的修改..." aria-label="提供编辑建议" title="提供编辑建议"><i class="material-icons" aria-hidden="true" role="img">mode_edit</i></a></div><div class="content"><h1 id="displaying-data" translation-result="on">显示数据<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/displaying-data#displaying-data"><i class="material-icons">link</i></a></h1><aio-toc class="embedded" ng-version="9.0.0-rc.11"><div class="toc-inner no-print collapsed ng-star-inserted"><button type="button" title="Expand/collapse contents" aria-label="Expand/collapse contents" class="toc-heading embedded secondary ng-star-inserted" aria-pressed="false">目录<mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon collapsed mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><ul class="toc-list embedded"><li class="h2 ng-star-inserted" title="使用插值显示组件属性"><a href="guide/displaying-data#showing-component-properties-with-interpolation">使用插值显示组件属性</a></li><li class="h2 ng-star-inserted" title="内联 (inline) 模板还是模板文件？"><a href="guide/displaying-data#template-inline-or-template-file">内联 (inline) 模板还是模板文件？</a></li><li class="h2 ng-star-inserted" title="使用构造函数还是变量初始化？"><a href="guide/displaying-data#constructor-or-variable-initialization">使用构造函数还是变量初始化？</a></li><li class="h2 secondary ng-star-inserted" title="使用 ngFor 显示数组属性"><a href="guide/displaying-data#showing-an-array-property-with-ngfor">使用 <strong><em>ngFor</em></strong> 显示数组属性</a></li><li class="h2 secondary ng-star-inserted" title="为数据创建一个类"><a href="guide/displaying-data#creating-a-class-for-the-data">为数据创建一个类</a></li><li class="h3 secondary ng-star-inserted" title="使用 Hero 类"><a href="guide/displaying-data#using-the-hero-class">使用 Hero 类</a></li><li class="h2 secondary ng-star-inserted" title="通过 NgIf 进行条件显示"><a href="guide/displaying-data#conditional-display-with-ngif">通过 NgIf 进行条件显示</a></li><li class="h2 secondary ng-star-inserted" title="小结"><a href="guide/displaying-data#summary">小结</a></li></ul><button type="button" title="Expand/collapse contents" aria-label="Expand/collapse contents" class="toc-more-items embedded material-icons collapsed ng-star-inserted" aria-pressed="false"></button></div></aio-toc><h1 translation-origin="off" id="displaying-data">Displaying data<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/displaying-data#displaying-data"><i class="material-icons">link</i></a></h1><p translation-result="on">你可以通过把 HTML 模板中的控件绑定到 Angular 组件的属性来显示数据。</p><p translation-origin="off">You can display data by binding controls in an HTML template to properties of an Angular component.</p><p translation-result="on">本章中，你将创建一个带英雄列表的组件。 你将显示英雄名字的列表，并根据条件在列表下方显示一条消息。</p><p translation-origin="off">In this page, you'll create a component with a list of heroes. You'll display the list of hero names and conditionally show a message below the list.</p><p translation-result="on">最终的用户界面是这样的：</p><p translation-origin="off">The final UI looks like this:</p><div class="lightbox"><img src="generated/images/guide/displaying-data/final.png" alt="Final UI" width="374" height="290"></div><div class="alert is-helpful"><p translation-result="on">这个<live-example ng-version="9.0.0-rc.11"><span style="display:none"></span><span><span class="ng-star-inserted"><a target="_blank" title="在线例子" href="generated/live-examples/displaying-data/stackblitz.html">在线例子</a><span class="ng-star-inserted"> / <a download="" title="下载范例" href="generated/zips/displaying-data/displaying-data.zip">下载范例</a></span></span></span></live-example>演示了本章中描述的所有语法和代码片段。</p><p translation-origin="off">The<live-example ng-version="9.0.0-rc.11"><span style="display:none"></span><span><span class="ng-star-inserted"><a target="_blank" title="在线例子" href="generated/live-examples/displaying-data/stackblitz.html">在线例子</a><span class="ng-star-inserted"> / <a download="" title="下载范例" href="generated/zips/displaying-data/displaying-data.zip">下载范例</a></span></span></span></live-example>demonstrates all of the syntax and code snippets described in this page.</p></div><a id="interpolation"></a><h2 id="showing-component-properties-with-interpolation" translation-result="on">使用插值显示组件属性<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/displaying-data#showing-component-properties-with-interpolation"><i class="material-icons">link</i></a></h2><h2 translation-origin="off" id="showing-component-properties-with-interpolation">Showing component properties with interpolation<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/displaying-data#showing-component-properties-with-interpolation"><i class="material-icons">link</i></a></h2><p translation-result="on">要显示组件的属性，最简单的方式就是通过插值 (interpolation) 来绑定属性名。 要使用插值，就把属性名包裹在双花括号里放进视图模板，如 <code>{{myHero}}</code>。</p><p translation-origin="off">The easiest way to display a component property is to bind the property name through interpolation. With interpolation, you put the property name in the view template, enclosed in double curly braces: <code>{{myHero}}</code>.</p><p translation-result="on">使用 CLI 命令 <a href="cli/new"><code>ng new displaying-data</code></a>创建一个工作空间和一个名叫 <code>displaying-data</code> 的应用。</p><p translation-origin="off">Use the CLI command <a href="cli/new"><code>ng new displaying-data</code></a>to create a workspace and app named <code>displaying-data</code>.</p><p translation-result="on">删除 <code>app.component.html</code> 文件，这个范例中不再需要它了。</p><p translation-origin="off">Delete the <code>app.component.html</code> file. It is not needed for this example.</p><p translation-result="on">然后，到 <code>app.component.ts</code> 文件中修改组件的模板和代码。</p><p translation-origin="off">Then modify the <code>app.component.ts</code> file by changing the template and the body of the component.</p><p translation-result="on">修改完之后，它应该是这样的：</p><p translation-origin="off">When you're done, it should look like this:</p><code-example path="displaying-data/src/app/app.component.1.ts" header="src/app/app.component.ts" ng-version="9.0.0-rc.11"><div style="display:none">import { <a href="api/core/Component" class="code-anchor">Component</a> } from '@angular/core'; @<a href="api/core/Component" class="code-anchor">Component</a>({ selector: 'app-root', template: ` &lt;h1&gt;{{title}}&lt;/h1&gt; &lt;h2&gt;My favorite hero is: {{myHero}}&lt;/h2&gt; ` }) export class AppComponent { title = 'Tour of Heroes'; myHero = 'Windstorm'; }</div><header class="ng-star-inserted">src/app/app.component.ts</header><aio-code class="headed-code"><pre class="lang- prettyprint">      <button title="Copy code snippet" class="material-icons copy-button no-print ng-star-inserted" aria-label="Copy code snippet from src/app/app.component.ts">
        <span aria-hidden="true">content_copy</span>
      </button>
      <code class="animated fadeIn"><span class="kwd">import</span><span class="pln"> </span><span class="pun">{</span><span class="pln"> </span><a href="api/core/Component" class="code-anchor"><span class="typ">Component</span></a><span class="pln"> </span><span class="pun">}</span><span class="pln"> </span><span class="kwd">from</span><span class="pln"> </span><span class="str">'@angular/core'</span><span class="pun">;</span><span class="pln">

</span><span class="lit">@</span><a href="api/core/Component" class="code-anchor"><span class="lit">Component</span></a><span class="pun">({</span><span class="pln">
  selector</span><span class="pun">:</span><span class="pln"> </span><span class="str">'app-root'</span><span class="pun">,</span><span class="pln">
  </span><span class="kwd">template</span><span class="pun">:</span><span class="pln"> </span><span class="str">`
    &lt;h1&gt;{{title}}&lt;/h1&gt;
    &lt;h2&gt;My favorite hero is: {{myHero}}&lt;/h2&gt;
    `</span><span class="pln">
</span><span class="pun">})</span><span class="pln">
</span><span class="kwd">export</span><span class="pln"> </span><span class="kwd">class</span><span class="pln"> </span><span class="typ">AppComponent</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
  title </span><span class="pun">=</span><span class="pln"> </span><span class="str">'Tour of Heroes'</span><span class="pun">;</span><span class="pln">
  myHero </span><span class="pun">=</span><span class="pln"> </span><span class="str">'Windstorm'</span><span class="pun">;</span><span class="pln">
</span><span class="pun">}</span></code>
    </pre></aio-code></code-example><p translation-result="on">再把两个属性 <code>title</code> 和 <code>myHero</code> 添加到之前空白的组件中。</p><p translation-origin="off">You added two properties to the formerly empty component: <code>title</code> and <code>myHero</code>.</p><p translation-result="on">修改完的模板会使用双花括号形式的插值来显示这两个模板属性：</p><p translation-origin="off">The template displays the two component properties using double curly brace interpolation:</p><code-example path="displaying-data/src/app/app.component.1.ts" header="src/app/app.component.ts (template)" region="template" ng-version="9.0.0-rc.11"><div style="display:none">template: ` &lt;h1&gt;{{title}}&lt;/h1&gt; &lt;h2&gt;My favorite hero is: {{myHero}}&lt;/h2&gt; `</div><header class="ng-star-inserted">src/app/app.component.ts (template)</header><aio-code class="headed-code"><pre class="lang- prettyprint">      <button title="Copy code snippet" class="material-icons copy-button no-print ng-star-inserted" aria-label="Copy code snippet from src/app/app.component.ts (template)">
        <span aria-hidden="true">content_copy</span>
      </button>
      <code class="animated fadeIn"><span class="kwd">template</span><span class="pun">:</span><span class="pln"> </span><span class="str">`
  &lt;h1&gt;{{title}}&lt;/h1&gt;
  &lt;h2&gt;My favorite hero is: {{myHero}}&lt;/h2&gt;
  `</span></code>
    </pre></aio-code></code-example><div class="alert is-helpful"><p translation-result="on">模板是包在 ECMAScript 2015 反引号 (<code>`</code>) 中的一个多行字符串。 反引号 (<code>`</code>) — 注意，不是单引号 (') — 允许把一个字符串写在多行上， 使 HTML 模板更容易阅读。</p><p translation-origin="off">The template is a multi-line string within ECMAScript 2015 backticks (<code>`</code>). The backtick (<code>`</code>)—which is <em>not</em> the same character as a single quote (<code>'</code>)—allows you to compose a string over several lines, which makes the HTML more readable.</p></div><p translation-result="on">Angular 自动从组件中提取 <code>title</code> 和 <code>myHero</code> 属性的值，并且把这些值插入浏览器中。当这些属性发生变化时，Angular 就会自动刷新显示。</p><p translation-origin="off">Angular automatically pulls the value of the <code>title</code> and <code>myHero</code> properties from the component and inserts those values into the browser. Angular updates the display when these properties change.</p><div class="alert is-helpful"><p translation-result="on">严格来说，“重新显示”是在某些与视图有关的异步事件之后发生的，例如，按键、定时器完成或对 HTTP 请求的响应。</p><p translation-origin="off">More precisely, the redisplay occurs after some kind of asynchronous event related to the view, such as a keystroke, a timer completion, or a response to an HTTP request.</p></div><p translation-result="on">注意，你没有调用 <strong>new</strong> 来创建 <code>AppComponent</code> 类的实例，是 Angular 替你创建了它。那么它是如何创建的呢？</p><p translation-origin="off">Notice that you don't call <strong>new</strong> to create an instance of the <code>AppComponent</code> class. Angular is creating an instance for you. How?</p><p translation-result="on">注意 <code>@<a href="api/core/Component" class="code-anchor">Component</a></code> 装饰器中指定的 CSS 选择器 <code>selector</code>，它指定了一个叫 <code>&lt;app-root&gt;</code> 的元素。 该元素是 <code>index.html</code> 文件里的一个占位符。</p><p translation-origin="off">The CSS <code>selector</code> in the <code>@<a href="api/core/Component" class="code-anchor">Component</a></code> decorator specifies an element named <code>&lt;app-root&gt;</code>. That element is a placeholder in the body of your <code>index.html</code> file:</p><code-example path="displaying-data/src/index.html" header="src/index.html (body)" region="body" ng-version="9.0.0-rc.11"><div style="display:none">&lt;body&gt; &lt;app-root&gt;&lt;/app-root&gt; &lt;/body&gt;</div><header class="ng-star-inserted">src/index.html (body)</header><aio-code class="headed-code"><pre class="lang- prettyprint">      <button title="Copy code snippet" class="material-icons copy-button no-print ng-star-inserted" aria-label="Copy code snippet from src/index.html (body)">
        <span aria-hidden="true">content_copy</span>
      </button>
      <code class="animated fadeIn"><span class="tag">&lt;body&gt;</span><span class="pln">
  </span><span class="tag">&lt;app-root&gt;&lt;/app-root&gt;</span><span class="pln">
</span><span class="tag">&lt;/body&gt;</span></code>
    </pre></aio-code></code-example><p translation-result="on">当你通过 <code>main.ts</code> 中的 <code>AppComponent</code> 类启动时，Angular 在 <code>index.html</code> 中查找一个 <code>&lt;app-root&gt;</code> 元素， 然后实例化一个 <code>AppComponent</code>，并将其渲染到 <code>&lt;app-root&gt;</code> 标签中。</p><p translation-origin="off">When you bootstrap with the <code>AppComponent</code> class (in <code>main.ts</code>), Angular looks for a <code>&lt;app-root&gt;</code> in the <code>index.html</code>, finds it, instantiates an instance of <code>AppComponent</code>, and renders it inside the <code>&lt;app-root&gt;</code> tag.</p><p translation-result="on">运行应用。它应该显示出标题和英雄名：</p><p translation-origin="off">Now run the app. It should display the title and hero name:</p><div class="lightbox"><img src="generated/images/guide/displaying-data/title-and-hero.png" alt="Title and Hero" width="348" height="108"></div><p translation-result="on">回顾一下前面所做的决定，看看还有哪些其它选择。</p><p translation-origin="off">The next few sections review some of the coding choices in the app.</p><h2 id="template-inline-or-template-file" translation-result="on">内联 (inline) 模板还是模板文件？<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/displaying-data#template-inline-or-template-file"><i class="material-icons">link</i></a></h2><h2 translation-origin="off" id="template-inline-or-template-file">Template inline or template file?<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/displaying-data#template-inline-or-template-file"><i class="material-icons">link</i></a></h2><p translation-result="on">你可以在两种地方存放组件模板。 你可以使用 <code>template</code> 属性把它定义为<em>内联</em>的，或者把模板定义在一个独立的 HTML 文件中， 再通过 <code>@<a href="api/core/Component" class="code-anchor">Component</a></code> 装饰器中的 <code><a href="api/core/Component#templateUrl" class="code-anchor">templateUrl</a></code> 属性， 在组件元数据中把它链接到组件。</p><p translation-origin="off">You can store your component's template in one of two places. You can define it <em>inline</em> using the <code>template</code> property, or you can define the template in a separate HTML file and link to it in the component metadata using the <code>@<a href="api/core/Component" class="code-anchor">Component</a></code> decorator's <code><a href="api/core/Component#templateUrl" class="code-anchor">templateUrl</a></code> property.</p><p translation-result="on">到底选择内联 HTML 还是独立 HTML 取决于个人喜好、具体状况和组织级策略。 上面的应用选择内联 HTML ，是因为模板很小，而且没有额外的 HTML 文件显得这个演示简单些。</p><p translation-origin="off">The choice between inline and separate HTML is a matter of taste, circumstances, and organization policy. Here the app uses inline HTML because the template is small and the demo is simpler without the additional HTML file.</p><p translation-result="on">无论用哪种风格，模板数据绑定在访问组件属性方面都是完全一样的。</p><p translation-origin="off">In either style, the template data bindings have the same access to the component's properties.</p><div class="alert is-helpful"><p translation-result="on">默认情况下，Angular CLI 命令 <a href="cli/generate"><code>ng generate component</code></a>在生成组件时会带有模板文件，你可以通过参数来覆盖它：</p><p translation-origin="off">By default, the Angular CLI command <a href="cli/generate"><code>ng generate component</code></a>generates components with a template file. You can override that with:</p><code-example hidecopy="" language="sh" class="code-shell" ng-version="9.0.0-rc.11"><div style="display:none">ng generate component hero -it</div><aio-code><pre class="lang-sh prettyprint">      
      <code class="animated fadeIn"><span class="pln">ng generate component hero </span><span class="pun">-</span><span class="pln">it</span></code>
    </pre></aio-code></code-example></div><h2 id="constructor-or-variable-initialization" translation-result="on">使用构造函数还是变量初始化？<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/displaying-data#constructor-or-variable-initialization"><i class="material-icons">link</i></a></h2><h2 translation-origin="off" id="constructor-or-variable-initialization">Constructor or variable initialization?<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/displaying-data#constructor-or-variable-initialization"><i class="material-icons">link</i></a></h2><p translation-result="on">虽然这个例子使用了变量赋值的方式初始化组件，你还可以使用构造函数来声明和初始化属性。</p><p translation-origin="off">Although this example uses variable assignment to initialize the components, you could instead declare and initialize the properties using a constructor:</p><code-example path="displaying-data/src/app/app-ctor.component.1.ts" region="class" ng-version="9.0.0-rc.11"><div style="display:none">export class AppComponent { title: string; myHero: string; constructor() { this.title = 'Tour of Heroes'; this.myHero = 'Windstorm'; } }</div><aio-code><pre class="lang- prettyprint">      <button title="Copy code snippet" class="material-icons copy-button no-print ng-star-inserted" aria-label="">
        <span aria-hidden="true">content_copy</span>
      </button>
      <code class="animated fadeIn"><span class="kwd">export</span><span class="pln"> </span><span class="kwd">class</span><span class="pln"> </span><span class="typ">AppComponent</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
  title</span><span class="pun">:</span><span class="pln"> </span><span class="kwd">string</span><span class="pun">;</span><span class="pln">
  myHero</span><span class="pun">:</span><span class="pln"> </span><span class="kwd">string</span><span class="pun">;</span><span class="pln">

  </span><span class="kwd">constructor</span><span class="pun">()</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
    </span><span class="kwd">this</span><span class="pun">.</span><span class="pln">title </span><span class="pun">=</span><span class="pln"> </span><span class="str">'Tour of Heroes'</span><span class="pun">;</span><span class="pln">
    </span><span class="kwd">this</span><span class="pun">.</span><span class="pln">myHero </span><span class="pun">=</span><span class="pln"> </span><span class="str">'Windstorm'</span><span class="pun">;</span><span class="pln">
  </span><span class="pun">}</span><span class="pln">
</span><span class="pun">}</span></code>
    </pre></aio-code></code-example><p translation-result="on">为了让本应用更加简短，它采用了更简单的“变量赋值”风格。</p><p translation-origin="off">This app uses more terse "variable assignment" style simply for brevity.</p><a id="ngFor"></a><h2 id="showing-an-array-property-with-ngfor" translation-result="on">使用 <strong><em>ngFor</em></strong> 显示数组属性<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/displaying-data#showing-an-array-property-with-ngfor"><i class="material-icons">link</i></a></h2><h2 translation-origin="off" id="showing-an-array-property-with-ngfor">Showing an array property with <strong>*ngFor</strong><a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/displaying-data#showing-an-array-property-with-ngfor"><i class="material-icons">link</i></a></h2><p translation-result="on">要显示一个英雄列表，先向组件中添加一个英雄名字数组，然后把 <code>myHero</code> 重定义为数组中的第一个名字。</p><p translation-origin="off">To display a list of heroes, begin by adding an array of hero names to the component and redefine <code>myHero</code> to be the first name in the array.</p><code-example path="displaying-data/src/app/app.component.2.ts" header="src/app/app.component.ts (class)" region="class" ng-version="9.0.0-rc.11"><div style="display:none">export class AppComponent { title = 'Tour of Heroes'; heroes = ['Windstorm', 'Bombasto', 'Magneta', 'Tornado']; myHero = this.heroes[0]; }</div><header class="ng-star-inserted">src/app/app.component.ts (class)</header><aio-code class="headed-code"><pre class="lang- prettyprint">      <button title="Copy code snippet" class="material-icons copy-button no-print ng-star-inserted" aria-label="Copy code snippet from src/app/app.component.ts (class)">
        <span aria-hidden="true">content_copy</span>
      </button>
      <code class="animated fadeIn"><span class="kwd">export</span><span class="pln"> </span><span class="kwd">class</span><span class="pln"> </span><span class="typ">AppComponent</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
  title </span><span class="pun">=</span><span class="pln"> </span><span class="str">'Tour of Heroes'</span><span class="pun">;</span><span class="pln">
  heroes </span><span class="pun">=</span><span class="pln"> </span><span class="pun">[</span><span class="str">'Windstorm'</span><span class="pun">,</span><span class="pln"> </span><span class="str">'Bombasto'</span><span class="pun">,</span><span class="pln"> </span><span class="str">'Magneta'</span><span class="pun">,</span><span class="pln"> </span><span class="str">'Tornado'</span><span class="pun">];</span><span class="pln">
  myHero </span><span class="pun">=</span><span class="pln"> </span><span class="kwd">this</span><span class="pun">.</span><span class="pln">heroes</span><span class="pun">[</span><span class="lit">0</span><span class="pun">];</span><span class="pln">
</span><span class="pun">}</span></code>
    </pre></aio-code></code-example><p translation-result="on">接着，在模板中使用 Angular 的 <code><a href="api/common/NgForOf" class="code-anchor">ngFor</a></code> 指令来显示 <code>heroes</code> 列表中的每一项。</p><p translation-origin="off">Now use the Angular <code><a href="api/common/NgForOf" class="code-anchor">ngFor</a></code> directive in the template to display each item in the <code>heroes</code> list.</p><code-example path="displaying-data/src/app/app.component.2.ts" header="src/app/app.component.ts (template)" region="template" ng-version="9.0.0-rc.11"><div style="display:none">template: ` &lt;h1&gt;{{title}}&lt;/h1&gt; &lt;h2&gt;My favorite hero is: {{myHero}}&lt;/h2&gt; &lt;p&gt;Heroes:&lt;/p&gt; &lt;ul&gt; &lt;li *<a href="api/common/NgForOf" class="code-anchor">ngFor</a>="let hero of heroes"&gt; {{ hero }} &lt;/li&gt; &lt;/ul&gt; `</div><header class="ng-star-inserted">src/app/app.component.ts (template)</header><aio-code class="headed-code"><pre class="lang- prettyprint">      <button title="Copy code snippet" class="material-icons copy-button no-print ng-star-inserted" aria-label="Copy code snippet from src/app/app.component.ts (template)">
        <span aria-hidden="true">content_copy</span>
      </button>
      <code class="animated fadeIn"><span class="kwd">template</span><span class="pun">:</span><span class="pln"> </span><span class="str">`
  &lt;h1&gt;{{title}}&lt;/h1&gt;
  &lt;h2&gt;My favorite hero is: {{myHero}}&lt;/h2&gt;
  &lt;p&gt;Heroes:&lt;/p&gt;
  &lt;ul&gt;
    &lt;li *</span><a href="api/common/NgForOf" class="code-anchor"><span class="str">ngFor</span></a><span class="str">="let hero of heroes"&gt;
      {{ hero }}
    &lt;/li&gt;
  &lt;/ul&gt;
`</span></code>
    </pre></aio-code></code-example><p translation-result="on">这个界面使用了由 <code>&lt;ul&gt;</code> 和 <code>&lt;li&gt;</code> 标签组成的无序列表。<code>&lt;li&gt;</code> 元素里的 <code>*<a href="api/common/NgForOf" class="code-anchor">ngFor</a></code> 是 Angular 的“迭代”指令。 它将 <code>&lt;li&gt;</code> 元素及其子级标记为“迭代模板”：</p><p translation-origin="off">This UI uses the HTML unordered list with <code>&lt;ul&gt;</code> and <code>&lt;li&gt;</code> tags. The <code>*<a href="api/common/NgForOf" class="code-anchor">ngFor</a></code> in the <code>&lt;li&gt;</code> element is the Angular "repeater" directive. It marks that <code>&lt;li&gt;</code> element (and its children) as the "repeater template":</p><code-example path="displaying-data/src/app/app.component.2.ts" header="src/app/app.component.ts (li)" region="li" ng-version="9.0.0-rc.11"><div style="display:none">&lt;li *<a href="api/common/NgForOf" class="code-anchor">ngFor</a>="let hero of heroes"&gt; {{ hero }} &lt;/li&gt;</div><header class="ng-star-inserted">src/app/app.component.ts (li)</header><aio-code class="headed-code"><pre class="lang- prettyprint">      <button title="Copy code snippet" class="material-icons copy-button no-print ng-star-inserted" aria-label="Copy code snippet from src/app/app.component.ts (li)">
        <span aria-hidden="true">content_copy</span>
      </button>
      <code class="animated fadeIn"><span class="tag">&lt;li</span><span class="pln"> *</span><a href="api/common/NgForOf" class="code-anchor"><span class="atn">ngFor</span></a><span class="pun">=</span><span class="atv">"let hero of heroes"</span><span class="tag">&gt;</span><span class="pln">
  {{ hero }}
</span><span class="tag">&lt;/li&gt;</span></code>
    </pre></aio-code></code-example><div class="alert is-important"><p translation-result="on">不要忘记 <code>*<a href="api/common/NgForOf" class="code-anchor">ngFor</a></code> 中的前导星号 (*)。它是语法中不可或缺的一部分。 更多信息，见<a href="guide/template-syntax#ngFor">模板语法</a>。</p><p translation-origin="off">Don't forget the leading asterisk (*) in <code>*<a href="api/common/NgForOf" class="code-anchor">ngFor</a></code>. It is an essential part of the syntax. For more information, see the <a href="guide/template-syntax#ngFor">Template Syntax</a> page.</p></div><p translation-result="on">注意看 <code><a href="api/common/NgForOf" class="code-anchor">ngFor</a></code> 双引号表达式中的 <code>hero</code>，它是一个模板输入变量。 更多模板输入变量的信息，见<a href="guide/template-syntax">模板语法</a>中的 <a href="guide/template-syntax#microsyntax">微语法 (microsyntax)</a>。</p><p translation-origin="off">Notice the <code>hero</code> in the <code><a href="api/common/NgForOf" class="code-anchor">ngFor</a></code> double-quoted instruction; it is an example of a template input variable. Read more about template input variables in the <a href="guide/template-syntax#microsyntax">microsyntax</a> section of the <a href="guide/template-syntax">Template Syntax</a> page.</p><p translation-result="on">Angular 为列表中的每个条目复制一个 <code>&lt;li&gt;</code> 元素，在每个迭代中，把 <code>hero</code> 变量设置为当前条目（英雄）。 Angular 把 <code>hero</code> 变量作为双花括号插值的上下文。</p><p translation-origin="off">Angular duplicates the <code>&lt;li&gt;</code> for each item in the list, setting the <code>hero</code> variable to the item (the hero) in the current iteration. Angular uses that variable as the context for the interpolation in the double curly braces.</p><div class="alert is-helpful"><p translation-result="on">本例中，<code><a href="api/common/NgForOf" class="code-anchor">ngFor</a></code> 用于显示一个“数组”， 但 <code><a href="api/common/NgForOf" class="code-anchor">ngFor</a></code> 可以为任何<a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Iteration_protocols">可迭代的 (iterable) </a>对象重复渲染条目。</p><p translation-origin="off">In this case, <code><a href="api/common/NgForOf" class="code-anchor">ngFor</a></code> is displaying an array, but <code><a href="api/common/NgForOf" class="code-anchor">ngFor</a></code> can repeat items for any <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Iteration_protocols">iterable</a> object.</p></div><p translation-result="on">现在，英雄们出现在了一个无序列表中。</p><p translation-origin="off">Now the heroes appear in an unordered list.</p><div class="lightbox"><img src="generated/images/guide/displaying-data/hero-names-list.png" alt="After ngfor" width="350" height="239"></div><h2 id="creating-a-class-for-the-data" translation-result="on">为数据创建一个类<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/displaying-data#creating-a-class-for-the-data"><i class="material-icons">link</i></a></h2><h2 translation-origin="off" id="creating-a-class-for-the-data">Creating a class for the data<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/displaying-data#creating-a-class-for-the-data"><i class="material-icons">link</i></a></h2><p translation-result="on">应用代码直接在组件内部直接定义了数据。 作为演示还可以，但它显然不是最佳实践。</p><p translation-origin="off">The app's code defines the data directly inside the component, which isn't best practice. In a simple demo, however, it's fine.</p><p translation-result="on">现在使用的是到了一个字符串数组的绑定。在真实的应用中，大多是到一个对象数组的绑定。</p><p translation-origin="off">At the moment, the binding is to an array of strings. In real applications, most bindings are to more specialized objects.</p><p translation-result="on">要将此绑定转换成使用对象，需要把这个英雄名字数组变成 <code>Hero</code> 对象数组。但首先得有一个 <code>Hero</code> 类。</p><p translation-origin="off">To convert this binding to use specialized objects, turn the array of hero names into an array of <code>Hero</code> objects. For that you'll need a <code>Hero</code> class:</p><code-example language="sh" class="code-shell" ng-version="9.0.0-rc.11"><div style="display:none">ng generate class hero</div><aio-code><pre class="lang-sh prettyprint">      <button title="Copy code snippet" class="material-icons copy-button no-print ng-star-inserted" aria-label="">
        <span aria-hidden="true">content_copy</span>
      </button>
      <code class="animated fadeIn"><span class="pln">ng generate class hero</span></code>
    </pre></aio-code></code-example><p translation-result="on">代码如下：</p><p translation-origin="off">With the following code:</p><code-example path="displaying-data/src/app/hero.ts" header="src/app/hero.ts" ng-version="9.0.0-rc.11"><div style="display:none">export class Hero { constructor( public id: number, public name: string) { } }</div><header class="ng-star-inserted">src/app/hero.ts</header><aio-code class="headed-code"><pre class="lang- prettyprint">      <button title="Copy code snippet" class="material-icons copy-button no-print ng-star-inserted" aria-label="Copy code snippet from src/app/hero.ts">
        <span aria-hidden="true">content_copy</span>
      </button>
      <code class="animated fadeIn"><span class="kwd">export</span><span class="pln"> </span><span class="kwd">class</span><span class="pln"> </span><span class="typ">Hero</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
  </span><span class="kwd">constructor</span><span class="pun">(</span><span class="pln">
    </span><span class="kwd">public</span><span class="pln"> id</span><span class="pun">:</span><span class="pln"> number</span><span class="pun">,</span><span class="pln">
    </span><span class="kwd">public</span><span class="pln"> name</span><span class="pun">:</span><span class="pln"> </span><span class="kwd">string</span><span class="pun">)</span><span class="pln"> </span><span class="pun">{</span><span class="pln"> </span><span class="pun">}</span><span class="pln">
</span><span class="pun">}</span></code>
    </pre></aio-code></code-example><p translation-result="on">你定义了一个类，具有一个构造函数和两个属性：<code>id</code> 和 <code>name</code>。</p><p translation-origin="off">You've defined a class with a constructor and two properties: <code>id</code> and <code>name</code>.</p><p translation-result="on">它可能看上去不像是有属性的类，但它确实有，利用的是 TypeScript 提供的简写形式 —— 用构造函数的参数直接定义属性。</p><p translation-origin="off">It might not look like the class has properties, but it does. The declaration of the constructor parameters takes advantage of a TypeScript shortcut.</p><p translation-result="on">来看第一个参数：</p><p translation-origin="off">Consider the first parameter:</p><code-example path="displaying-data/src/app/hero.ts" header="src/app/hero.ts (id)" region="id" ng-version="9.0.0-rc.11"><div style="display:none">public id: number,</div><header class="ng-star-inserted">src/app/hero.ts (id)</header><aio-code class="headed-code"><pre class="lang- prettyprint">      <button title="Copy code snippet" class="material-icons copy-button no-print ng-star-inserted" aria-label="Copy code snippet from src/app/hero.ts (id)">
        <span aria-hidden="true">content_copy</span>
      </button>
      <code class="animated fadeIn"><span class="kwd">public</span><span class="pln"> id</span><span class="pun">:</span><span class="pln"> number</span><span class="pun">,</span></code>
    </pre></aio-code></code-example><p translation-result="on">这个简写语法做了很多：</p><p translation-origin="off">That brief syntax does a lot:</p><ul><li><p translation-result="on">声明了一个构造函数参数及其类型。</p><p translation-origin="off">Declares a constructor parameter and its type.</p></li><li><p translation-result="on">声明了一个同名的公共属性。</p><p translation-origin="off">Declares a public property of the same name.</p></li><li><p translation-result="on">当创建该类的一个实例时，把该属性初始化为相应的参数值。</p><p translation-origin="off">Initializes that property with the corresponding argument when creating an instance of the class.</p></li></ul><h3 id="using-the-hero-class" translation-result="on">使用 Hero 类<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/displaying-data#using-the-hero-class"><i class="material-icons">link</i></a></h3><h3 translation-origin="off" id="using-the-hero-class">Using the Hero class<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/displaying-data#using-the-hero-class"><i class="material-icons">link</i></a></h3><p translation-result="on">导入了 <code>Hero</code> 类之后，组件的 <code>heroes</code> 属性就可以返回一个<em>类型化的</em><code>Hero</code> 对象数组了。</p><p translation-origin="off">After importing the <code>Hero</code> class, the <code>AppComponent.heroes</code> property can return a <em>typed</em> array of <code>Hero</code> objects:</p><code-example path="displaying-data/src/app/app.component.3.ts" header="src/app/app.component.ts (heroes)" region="heroes" ng-version="9.0.0-rc.11"><div style="display:none">heroes = [ new Hero(1, 'Windstorm'), new Hero(13, 'Bombasto'), new Hero(15, 'Magneta'), new Hero(20, 'Tornado') ]; myHero = this.heroes[0];</div><header class="ng-star-inserted">src/app/app.component.ts (heroes)</header><aio-code class="headed-code"><pre class="lang- prettyprint">      <button title="Copy code snippet" class="material-icons copy-button no-print ng-star-inserted" aria-label="Copy code snippet from src/app/app.component.ts (heroes)">
        <span aria-hidden="true">content_copy</span>
      </button>
      <code class="animated fadeIn"><span class="pln">heroes </span><span class="pun">=</span><span class="pln"> </span><span class="pun">[</span><span class="pln">
  </span><span class="kwd">new</span><span class="pln"> </span><span class="typ">Hero</span><span class="pun">(</span><span class="lit">1</span><span class="pun">,</span><span class="pln"> </span><span class="str">'Windstorm'</span><span class="pun">),</span><span class="pln">
  </span><span class="kwd">new</span><span class="pln"> </span><span class="typ">Hero</span><span class="pun">(</span><span class="lit">13</span><span class="pun">,</span><span class="pln"> </span><span class="str">'Bombasto'</span><span class="pun">),</span><span class="pln">
  </span><span class="kwd">new</span><span class="pln"> </span><span class="typ">Hero</span><span class="pun">(</span><span class="lit">15</span><span class="pun">,</span><span class="pln"> </span><span class="str">'Magneta'</span><span class="pun">),</span><span class="pln">
  </span><span class="kwd">new</span><span class="pln"> </span><span class="typ">Hero</span><span class="pun">(</span><span class="lit">20</span><span class="pun">,</span><span class="pln"> </span><span class="str">'Tornado'</span><span class="pun">)</span><span class="pln">
</span><span class="pun">];</span><span class="pln">
myHero </span><span class="pun">=</span><span class="pln"> </span><span class="kwd">this</span><span class="pun">.</span><span class="pln">heroes</span><span class="pun">[</span><span class="lit">0</span><span class="pun">];</span></code>
    </pre></aio-code></code-example><p translation-result="on">接着，修改模板。 现在它显示的是英雄的 <code>id</code> 和 <code>name</code>。 要修复它，只显示英雄的 <code>name</code> 属性就行了。</p><p translation-origin="off">Next, update the template. At the moment it displays the hero's <code>id</code> and <code>name</code>. Fix that to display only the hero's <code>name</code> property.</p><code-example path="displaying-data/src/app/app.component.3.ts" header="src/app/app.component.ts (template)" region="template" ng-version="9.0.0-rc.11"><div style="display:none">template: ` &lt;h1&gt;{{title}}&lt;/h1&gt; &lt;h2&gt;My favorite hero is: {{myHero.name}}&lt;/h2&gt; &lt;p&gt;Heroes:&lt;/p&gt; &lt;ul&gt; &lt;li *<a href="api/common/NgForOf" class="code-anchor">ngFor</a>="let hero of heroes"&gt; {{ hero.name }} &lt;/li&gt; &lt;/ul&gt; `</div><header class="ng-star-inserted">src/app/app.component.ts (template)</header><aio-code class="headed-code"><pre class="lang- prettyprint">      <button title="Copy code snippet" class="material-icons copy-button no-print ng-star-inserted" aria-label="Copy code snippet from src/app/app.component.ts (template)">
        <span aria-hidden="true">content_copy</span>
      </button>
      <code class="animated fadeIn"><span class="kwd">template</span><span class="pun">:</span><span class="pln"> </span><span class="str">`
  &lt;h1&gt;{{title}}&lt;/h1&gt;
  &lt;h2&gt;My favorite hero is: {{myHero.name}}&lt;/h2&gt;
  &lt;p&gt;Heroes:&lt;/p&gt;
  &lt;ul&gt;
    &lt;li *</span><a href="api/common/NgForOf" class="code-anchor"><span class="str">ngFor</span></a><span class="str">="let hero of heroes"&gt;
      {{ hero.name }}
    &lt;/li&gt;
  &lt;/ul&gt;
`</span></code>
    </pre></aio-code></code-example><p translation-result="on">显示上还和以前一样，不过代码更清晰了。</p><p translation-origin="off">The display looks the same, but the code is clearer.</p><a id="ngIf"></a><h2 id="conditional-display-with-ngif" translation-result="on">通过 NgIf 进行条件显示<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/displaying-data#conditional-display-with-ngif"><i class="material-icons">link</i></a></h2><h2 translation-origin="off" id="conditional-display-with-ngif">Conditional display with NgIf<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/displaying-data#conditional-display-with-ngif"><i class="material-icons">link</i></a></h2><p translation-result="on">有时，应用需要只在特定情况下显示视图或视图的一部分。</p><p translation-origin="off">Sometimes an app needs to display a view or a portion of a view only under specific circumstances.</p><p translation-result="on">来改一下这个例子，如果多于三位英雄，显示一条消息。</p><p translation-origin="off">Let's change the example to display a message if there are more than three heroes.</p><p translation-result="on">Angular 的 <code><a href="api/common/NgIf" class="code-anchor">ngIf</a></code> 指令会根据一个布尔条件来显示或移除一个元素。 来看看实际效果，把下列语句加到模板的底部：</p><p translation-origin="off">The Angular <code><a href="api/common/NgIf" class="code-anchor">ngIf</a></code> directive inserts or removes an element based on a <em>truthy/falsy</em> condition. To see it in action, add the following paragraph at the bottom of the template:</p><code-example path="displaying-data/src/app/app.component.ts" header="src/app/app.component.ts (message)" region="message" ng-version="9.0.0-rc.11"><div style="display:none">&lt;p *<a href="api/common/NgIf" class="code-anchor">ngIf</a>="heroes.length &gt; 3"&gt;There are many heroes!&lt;/p&gt;</div><header class="ng-star-inserted">src/app/app.component.ts (message)</header><aio-code class="headed-code"><pre class="lang- prettyprint">      <button title="Copy code snippet" class="material-icons copy-button no-print ng-star-inserted" aria-label="Copy code snippet from src/app/app.component.ts (message)">
        <span aria-hidden="true">content_copy</span>
      </button>
      <code class="animated fadeIn"><span class="tag">&lt;p</span><span class="pln"> *</span><a href="api/common/NgIf" class="code-anchor"><span class="atn">ngIf</span></a><span class="pun">=</span><span class="atv">"heroes.length &gt;</span><span class="pln"> 3"&gt;There are many heroes!</span><span class="tag">&lt;/p&gt;</span></code>
    </pre></aio-code></code-example><div class="alert is-important"><p translation-result="on">不要忘了 <code>*<a href="api/common/NgIf" class="code-anchor">ngIf</a></code> 中的前导星号 (*)。它是本语法中不可或缺的一部分。 更多 <code><a href="api/common/NgIf" class="code-anchor">ngIf</a></code> 和 <code>*</code> 的内容，见<a href="guide/template-syntax">模板语法</a>中的<a href="guide/template-syntax#ngIf">ngIf</a>。</p><p translation-origin="off">Don't forget the leading asterisk (*) in <code>*<a href="api/common/NgIf" class="code-anchor">ngIf</a></code>. It is an essential part of the syntax. Read more about <code><a href="api/common/NgIf" class="code-anchor">ngIf</a></code> and <code>*</code> in the <a href="guide/template-syntax#ngIf">ngIf section</a> of the <a href="guide/template-syntax">Template Syntax</a> page.</p></div><p translation-result="on">双引号中的模板表达式 <code>*<a href="api/common/NgIf" class="code-anchor">ngIf</a>="heros.length &gt; 3"</code>，外观和行为很象 TypeScript 。 当组件中的英雄列表有三个以上的条目时，Angular 就会把这个段落添加到 DOM 中，于是消息显示了出来。 如果有三个或更少的条目，则 Angular 会省略这些段落，所以不显示消息。 更多信息，见<a href="guide/template-syntax">模板语法</a>中的<a href="guide/template-syntax#template-expressions">模板表达式</a>。</p><p translation-origin="off">The template expression inside the double quotes, <code>*<a href="api/common/NgIf" class="code-anchor">ngIf</a>="heroes.length &gt; 3"</code>, looks and behaves much like TypeScript. When the component's list of heroes has more than three items, Angular adds the paragraph to the DOM and the message appears. If there are three or fewer items, Angular omits the paragraph, so no message appears. For more information, see the <a href="guide/template-syntax#template-expressions">template expressions</a> section of the <a href="guide/template-syntax">Template Syntax</a> page.</p><div class="alert is-helpful"><p translation-result="on">Angular 并不是在显示和隐藏这条消息，它是在从 DOM 中添加和移除这个段落元素。 这会提高性能，特别是在一些大的项目中有条件地包含或排除一大堆带着很多数据绑定的 HTML 时。</p><p translation-origin="off">Angular isn't showing and hiding the message. It is adding and removing the paragraph element from the DOM. That improves performance, especially in larger projects when conditionally including or excluding big chunks of HTML with many data bindings.</p></div><p translation-result="on">试一下。因为这个数组中有四个条目，所以消息应该显示出来。 回到 <code>app.component.ts</code>，从英雄数组中删除或注释掉一个元素。 浏览器应该自动刷新，消息应该会消失。</p><p translation-origin="off">Try it out. Because the array has four items, the message should appear. Go back into <code>app.component.ts</code> and delete or comment out one of the elements from the heroes array. The browser should refresh automatically and the message should disappear.</p><h2 id="summary" translation-result="on">小结<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/displaying-data#summary"><i class="material-icons">link</i></a></h2><h2 translation-origin="off" id="summary">Summary<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/displaying-data#summary"><i class="material-icons">link</i></a></h2><p translation-result="on">现在你知道了如何使用：</p><p translation-origin="off">Now you know how to use:</p><ul><li><p translation-result="on">带有双花括号的<strong>插值 (interpolation) </strong>来显示一个组件属性。</p><p translation-origin="off"><strong>Interpolation</strong> with double curly braces to display a component property.</p></li><li><p translation-result="on">用 <strong>ngFor</strong> 显示数组。</p><p translation-origin="off"><strong>ngFor</strong> to display an array of items.</p></li><li><p translation-result="on">用一个 TypeScript 类来为你的组件描述<strong>模型数据</strong>并显示模型的属性。</p><p translation-origin="off">A TypeScript class to shape the <strong>model data</strong> for your component and display properties of that model.</p></li><li><p translation-result="on">用 <strong>ngIf</strong> 根据一个布尔表达式有条件地显示一段 HTML。</p><p translation-origin="off"><strong>ngIf</strong> to conditionally display a chunk of HTML based on a boolean expression.</p></li></ul><p translation-result="on">下面是最终的代码：</p><p translation-origin="off">Here's the final code:</p><code-tabs ng-version="9.0.0-rc.11"><div style="display:none"><code-pane header="src/app/app.component.ts" path="displaying-data/src/app/app.component.ts" region="final">import { <a href="api/core/Component" class="code-anchor">Component</a> } from '@angular/core'; import { Hero } from './hero'; @<a href="api/core/Component" class="code-anchor">Component</a>({ selector: 'app-root', template: ` &lt;h1&gt;{{title}}&lt;/h1&gt; &lt;h2&gt;My favorite hero is: {{myHero.name}}&lt;/h2&gt; &lt;p&gt;Heroes:&lt;/p&gt; &lt;ul&gt; &lt;li *<a href="api/common/NgForOf" class="code-anchor">ngFor</a>="let hero of heroes"&gt; {{ hero.name }} &lt;/li&gt; &lt;/ul&gt; &lt;p *<a href="api/common/NgIf" class="code-anchor">ngIf</a>="heroes.length &gt; 3"&gt;There are many heroes!&lt;/p&gt; ` }) export class AppComponent { title = 'Tour of Heroes'; heroes = [ new Hero(1, 'Windstorm'), new Hero(13, 'Bombasto'), new Hero(15, 'Magneta'), new Hero(20, 'Tornado') ]; myHero = this.heroes[0]; }</code-pane><code-pane header="src/app/hero.ts" path="displaying-data/src/app/hero.ts">export class Hero { constructor( public id: number, public name: string) { } }</code-pane><code-pane header="src/app/app.module.ts" path="displaying-data/src/app/app.module.ts">import { <a href="api/core/NgModule" class="code-anchor">NgModule</a> } from '@angular/core'; import { <a href="api/platform-browser/BrowserModule" class="code-anchor">BrowserModule</a> } from '@angular/platform-browser'; import { AppComponent } from './app.component'; @<a href="api/core/NgModule" class="code-anchor">NgModule</a>({ imports: [ <a href="api/platform-browser/BrowserModule" class="code-anchor">BrowserModule</a> ], declarations: [ AppComponent ], bootstrap: [ AppComponent ] }) export class AppModule { }</code-pane><code-pane header="main.ts" path="displaying-data/src/main.ts">import { <a href="api/core/enableProdMode" class="code-anchor">enableProdMode</a> } from '@angular/core'; import { <a href="api/platform-browser-dynamic/platformBrowserDynamic" class="code-anchor">platformBrowserDynamic</a> } from '@angular/platform-browser-dynamic'; import { AppModule } from './app/app.module'; import { environment } from './environments/environment'; if (environment.production) { <a href="api/core/enableProdMode" class="code-anchor">enableProdMode</a>(); } <a href="api/platform-browser-dynamic/platformBrowserDynamic" class="code-anchor">platformBrowserDynamic</a>().bootstrapModule(AppModule);</code-pane></div><mat-card class="mat-card"><mat-tab-group class="mat-tab-group code-tab-group mat-primary"><mat-tab-header class="mat-tab-header"><div aria-hidden="true" mat-ripple="" class="mat-ripple mat-tab-header-pagination mat-tab-header-pagination-before mat-elevation-z4 mat-tab-header-pagination-disabled"><div class="mat-tab-header-pagination-chevron"></div></div><div class="mat-tab-label-container"><div role="tablist" class="mat-tab-list" style="transform:translateX(0)"><div class="mat-tab-labels"><div role="tab" mattablabelwrapper="" mat-ripple="" cdkmonitorelementfocus="" class="mat-ripple mat-tab-label mat-tab-label-active ng-star-inserted" id="mat-tab-label-0-0" tabindex="0" aria-posinset="1" aria-setsize="4" aria-controls="mat-tab-content-0-0" aria-selected="true" aria-disabled="false"><div class="mat-tab-label-content"><span class="ng-star-inserted">src/app/app.component.ts</span></div></div><div role="tab" mattablabelwrapper="" mat-ripple="" cdkmonitorelementfocus="" class="mat-ripple mat-tab-label ng-star-inserted" id="mat-tab-label-0-1" tabindex="-1" aria-posinset="2" aria-setsize="4" aria-controls="mat-tab-content-0-1" aria-selected="false" aria-disabled="false"><div class="mat-tab-label-content"><span class="ng-star-inserted">src/app/hero.ts</span></div></div><div role="tab" mattablabelwrapper="" mat-ripple="" cdkmonitorelementfocus="" class="mat-ripple mat-tab-label ng-star-inserted" id="mat-tab-label-0-2" tabindex="-1" aria-posinset="3" aria-setsize="4" aria-controls="mat-tab-content-0-2" aria-selected="false" aria-disabled="false"><div class="mat-tab-label-content"><span class="ng-star-inserted">src/app/app.module.ts</span></div></div><div role="tab" mattablabelwrapper="" mat-ripple="" cdkmonitorelementfocus="" class="mat-ripple mat-tab-label ng-star-inserted" id="mat-tab-label-0-3" tabindex="-1" aria-posinset="4" aria-setsize="4" aria-controls="mat-tab-content-0-3" aria-selected="false" aria-disabled="false"><div class="mat-tab-label-content"><span class="ng-star-inserted">main.ts</span></div></div></div><mat-ink-bar class="mat-ink-bar" style="visibility:visible;left:0;width:209px"></mat-ink-bar></div></div><div aria-hidden="true" mat-ripple="" class="mat-ripple mat-tab-header-pagination mat-tab-header-pagination-after mat-elevation-z4 mat-tab-header-pagination-disabled"><div class="mat-tab-header-pagination-chevron"></div></div></mat-tab-header><div class="mat-tab-body-wrapper"><mat-tab-body role="tabpanel" class="mat-tab-body ng-tns-c50-2 mat-tab-body-active ng-star-inserted" id="mat-tab-content-0-0" aria-labelledby="mat-tab-label-0-0"><div class="mat-tab-body-content ng-tns-c50-2 ng-trigger ng-trigger-translateTab" style="transform:none"><aio-code class="ng-star-inserted" style=""><pre class="lang- prettyprint">      <button title="Copy code snippet" class="material-icons copy-button no-print ng-star-inserted" aria-label="Copy code snippet from src/app/app.component.ts">
        <span aria-hidden="true">content_copy</span>
      </button>
      <code class="animated fadeIn"><span class="kwd">import</span><span class="pln"> </span><span class="pun">{</span><span class="pln"> </span><a href="api/core/Component" class="code-anchor"><span class="typ">Component</span></a><span class="pln"> </span><span class="pun">}</span><span class="pln"> </span><span class="kwd">from</span><span class="pln"> </span><span class="str">'@angular/core'</span><span class="pun">;</span><span class="pln">

</span><span class="kwd">import</span><span class="pln"> </span><span class="pun">{</span><span class="pln"> </span><span class="typ">Hero</span><span class="pln"> </span><span class="pun">}</span><span class="pln"> </span><span class="kwd">from</span><span class="pln"> </span><span class="str">'./hero'</span><span class="pun">;</span><span class="pln">

</span><span class="lit">@</span><a href="api/core/Component" class="code-anchor"><span class="lit">Component</span></a><span class="pun">({</span><span class="pln">
  selector</span><span class="pun">:</span><span class="pln"> </span><span class="str">'app-root'</span><span class="pun">,</span><span class="pln">
  </span><span class="kwd">template</span><span class="pun">:</span><span class="pln"> </span><span class="str">`
  &lt;h1&gt;{{title}}&lt;/h1&gt;
  &lt;h2&gt;My favorite hero is: {{myHero.name}}&lt;/h2&gt;
  &lt;p&gt;Heroes:&lt;/p&gt;
  &lt;ul&gt;
    &lt;li *</span><a href="api/common/NgForOf" class="code-anchor"><span class="str">ngFor</span></a><span class="str">="let hero of heroes"&gt;
      {{ hero.name }}
      &lt;/li&gt;
  &lt;/ul&gt;
  &lt;p *</span><a href="api/common/NgIf" class="code-anchor"><span class="str">ngIf</span></a><span class="str">="heroes.length &gt; 3"&gt;There are many heroes!&lt;/p&gt;
`</span><span class="pln">
</span><span class="pun">})</span><span class="pln">
</span><span class="kwd">export</span><span class="pln"> </span><span class="kwd">class</span><span class="pln"> </span><span class="typ">AppComponent</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
  title </span><span class="pun">=</span><span class="pln"> </span><span class="str">'Tour of Heroes'</span><span class="pun">;</span><span class="pln">
  heroes </span><span class="pun">=</span><span class="pln"> </span><span class="pun">[</span><span class="pln">
    </span><span class="kwd">new</span><span class="pln"> </span><span class="typ">Hero</span><span class="pun">(</span><span class="lit">1</span><span class="pun">,</span><span class="pln"> </span><span class="str">'Windstorm'</span><span class="pun">),</span><span class="pln">
    </span><span class="kwd">new</span><span class="pln"> </span><span class="typ">Hero</span><span class="pun">(</span><span class="lit">13</span><span class="pun">,</span><span class="pln"> </span><span class="str">'Bombasto'</span><span class="pun">),</span><span class="pln">
    </span><span class="kwd">new</span><span class="pln"> </span><span class="typ">Hero</span><span class="pun">(</span><span class="lit">15</span><span class="pun">,</span><span class="pln"> </span><span class="str">'Magneta'</span><span class="pun">),</span><span class="pln">
    </span><span class="kwd">new</span><span class="pln"> </span><span class="typ">Hero</span><span class="pun">(</span><span class="lit">20</span><span class="pun">,</span><span class="pln"> </span><span class="str">'Tornado'</span><span class="pun">)</span><span class="pln">
  </span><span class="pun">];</span><span class="pln">
  myHero </span><span class="pun">=</span><span class="pln"> </span><span class="kwd">this</span><span class="pun">.</span><span class="pln">heroes</span><span class="pun">[</span><span class="lit">0</span><span class="pun">];</span><span class="pln">
</span><span class="pun">}</span></code>
    </pre></aio-code></div></mat-tab-body><mat-tab-body role="tabpanel" class="mat-tab-body ng-tns-c50-3 ng-star-inserted" id="mat-tab-content-0-1" aria-labelledby="mat-tab-label-0-1"><div class="mat-tab-body-content ng-tns-c50-3 ng-trigger ng-trigger-translateTab" style="transform:translate3d(100%,0,0);min-height:1px"></div></mat-tab-body><mat-tab-body role="tabpanel" class="mat-tab-body ng-tns-c50-4 ng-star-inserted" id="mat-tab-content-0-2" aria-labelledby="mat-tab-label-0-2"><div class="mat-tab-body-content ng-tns-c50-4 ng-trigger ng-trigger-translateTab" style="transform:translate3d(100%,0,0);min-height:1px"></div></mat-tab-body><mat-tab-body role="tabpanel" class="mat-tab-body ng-tns-c50-5 ng-star-inserted" id="mat-tab-content-0-3" aria-labelledby="mat-tab-label-0-3"><div class="mat-tab-body-content ng-tns-c50-5 ng-trigger ng-trigger-translateTab" style="transform:translate3d(100%,0,0);min-height:1px"></div></mat-tab-body></div></mat-tab-group></mat-card></code-tabs></div></div></aio-doc-viewer></main></mat-sidenav-content></mat-sidenav-container><div class="toc-container no-print ng-star-inserted"><aio-lazy-ce selector="aio-toc"><aio-toc ng-version="9.0.0-rc.11"><div class="toc-inner no-print collapsed ng-star-inserted"><ul class="toc-list"><li class="h1 ng-star-inserted active" title="显示数据"><a href="guide/displaying-data#displaying-data">显示数据</a></li><li class="h2 ng-star-inserted" title="使用插值显示组件属性"><a href="guide/displaying-data#showing-component-properties-with-interpolation">使用插值显示组件属性</a></li><li class="h2 ng-star-inserted" title="内联 (inline) 模板还是模板文件？"><a href="guide/displaying-data#template-inline-or-template-file">内联 (inline) 模板还是模板文件？</a></li><li class="h2 ng-star-inserted" title="使用构造函数还是变量初始化？"><a href="guide/displaying-data#constructor-or-variable-initialization">使用构造函数还是变量初始化？</a></li><li class="h2 ng-star-inserted" title="使用 ngFor 显示数组属性"><a href="guide/displaying-data#showing-an-array-property-with-ngfor">使用 <strong><em>ngFor</em></strong> 显示数组属性</a></li><li class="h2 ng-star-inserted" title="为数据创建一个类"><a href="guide/displaying-data#creating-a-class-for-the-data">为数据创建一个类</a></li><li class="h3 ng-star-inserted" title="使用 Hero 类"><a href="guide/displaying-data#using-the-hero-class">使用 Hero 类</a></li><li class="h2 ng-star-inserted" title="通过 NgIf 进行条件显示"><a href="guide/displaying-data#conditional-display-with-ngif">通过 NgIf 进行条件显示</a></li><li class="h2 ng-star-inserted" title="小结"><a href="guide/displaying-data#summary">小结</a></li></ul></div></aio-toc></aio-lazy-ce></div><footer class="no-print"><aio-footer><div class="grid-fluid"><div class="footer-block ng-star-inserted"><h3>资源</h3><ul><li class="ng-star-inserted"><a class="link" href="about" title="Angular 贡献者。">关于</a></li><li class="ng-star-inserted"><a class="link" href="resources" title="网络上的 Angular 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